Radiator spiral coil tube



May 29, 1934.

w. o. EMMoNs Er Al.

RADIATOR SPIRAL COIL TUBE Filed Aug. 1o. 1953 Patented May 29, l1934 RADIATOR SPIRAL COIL TUBE Willard 0. Emmons, Lockport, and Joseph Williams, Medina, N. Y., signments, to General assignors, by mesne-as- Motors Corporation, De-

troit, Mich., a corporation of Delaware Application August 10,

4 Claims.

This invention relates to heat exchange devices. y and tube type of radiating elements and involves in a specific embodiment a fiat sided coil of flat 5 ribbon helically wound within one of its flat sides contacting with the peripheral surface of the tube.

Helically wound coils of round section wire with arcuate tube contacting portions have been prol posed heretofore, the engagement in such cases between the tube and the individual coils being merely a point contact, due to the fact that the tube abutting surfaces are oppositely curved. To improve upon past practice and secure better l transference of heat between the tube and 1in by materially increasing the ratio of tube contacting siuface to exposed n surface is one of the aims of the present invention.

A further object of the invention is to provide a 2.0 helical succession of fin loops radiating from the tube and spaced apart for the effective distribution thereabout of a heat transferring agent with each radiating element consisting of a relatively thin and wide ribbon so that for the amount of metal involved in the cross section of the ribbon a maximum of surface area is provided and .the

fin is of such small thickness that there will be no substantial storage of heat therein.

Other objects and advantages will become apparent during the course of the following detail specification having reference to the accompanying drawing, wherein Figure 1 is a perspective View of a small portion of finned tube, and Figure 2 is a detail perspective View of a short length of A coiled fin ready for wrapping on the tube.

Referring to the drawing, the numeral 1 indicates a hollow tube, preferably of thin metal and circular in section, affording a passage for the fiow of cooling or heating water or other fluid. Helically Wound upon the tube is a heat transferring member in the form of a continuous succession of rectangular or straight sided loops radially disposed and made up of a coiled fiat ribbon 2. l

The fiat ribbon 2 is coiled prior to its application to the tube by bending, at given intervals upon a suitable mandrel, a length of strip stock at an angle of 90 to the plane of the strip, thereby forming straight sides and ends in each succeeding turn with adjacent edges of adjoining turns abutting one another, as clearly shown in Figure 2. When the coil is then wrapped upon the tube 1, the tube contacting end portions of the loops retain their edge to edge abutment and present a substantially continuous interior More particularly, it has to do with fin I 193s, serial No. 684,498

cylindrical surface, as is plainly shown toward the left in Figure 2, with each end portion bearing on the peripheral surface and extending axially of the tube, while the straight sides and outer free ends radiate outwardly from the tube in spread apart relation to permit the relatively free fiow therearound of air or other heat transferring agent.

Each tube contacting end portion of the coiled ribbon 2 in intimate contact throughout its extent with the tube surface may be welded, soldered, or otherwise secured on the tube. If a soldered bond is used it may be effected by dipping the assembly in a molten solder bath or the tube may be solder coated prior to the application of the coil and later heated or a solder wire may be wrapped about the tube beside or within the coiled 1in element and heat applied thereto.

Either with or without the solder bond it will be found desirable to position inside the coil a binder or tensioning ribbon 3 of. flat stock, substantially corresponding in width to the axially extending' tube contacting end portions of the several loops. This insert or binder strip can be enclosed by the ribbon 2 at the time of coiling or threaded through the coiled fin, and when drawn tightly and anchored at opposite ends by soldering, welding or otherwise as at 4, securely holds the coil in place and draws the loo'p ends in firm contact with and tends to conform them more nearly to the cylindrical surface of the tube.

From the above description it will be seen that there is provided a device in which the coiled fin has a substantial surface area at each turn in direct intimate engagement with the tube surface to insure rapid transference of heat between the metals of the tube and radiating loop sides.

While only a preferred embodiment of the invention has been described specifically, it will be understood that such modifications may be made as come within the scope of the appended claims.

We claim:

1. In a heat exchanger, a tube and a 1in comprising a succession of flat sided loops of flat ribbon each fiat sided loop having one of its fiat sides in engagement throughout its area with the tube.

2. In a heat exchanger, a tube, a helically wound fin thereon, comprising a coil of fiat ribbon stock having a lfiat tube 'engaging portion and a flat ribbon threaded through said coil and means to secure the same helically wrapped upon the tube, with one side of each rectangular loop extending axially of the tube in llat contact therewithl throughout its length.

4. In aheat exchanger, a tube, a succession of flat sided loops of at ribbon stock encircling said tube with one side of each loop in at surface contact throughout its area with the tube and the tube engaging sides of the several loops in substantially edge to edge abutment to provide a continuous line of contact of substantial width, from which the other sides o! the loops radiate in spread apart relation.

WIILARD O. EMMONS. JOSEPH WILLIAMS. 

